TWI727099B - Diblock copolymer containing fluorine group - Google Patents

Abstract

Provided is a diblock copolymer comprising a first block having a repeating unit represented by the following Chemical Formula 1, and a second block having a repeating unit represented by the following Chemical Formula 2:

wherein R₁ to R₅, X₁ to X₅, l, n and m are as defined in claim 1.

Description

Fluorine-containing diblock copolymer

The following disclosure is about a diblock copolymer with excellent etching selectivity and the ability to form high-quality nano-patterns.

With the continuous demand for miniaturization and compactness of high-performance components, it is necessary to further reduce the distance between patterns (such as pattern line width (critical dimension, CD)) and the gap between patterns. Space is a technology used to produce high-density nano-patterns to achieve more patterns in a limited area.

As a method for forming nano-patterns, top-down photolithography can be cited. However, due to the limitation of the wavelength of the light source and the resolution of the optical system, the photolithography technology is limited in improving the resolution.

As one of the efforts to overcome the resolution limitation in lithography technology and to develop the next generation of micromachining technology, a bottom-up directed self-assembly (DSA) technology using molecular self-assembly is attracting attention (Korea Patent Publication No. 10-2016-0073408).

The advantage of DSA technology is that it is relatively simple. Compared with conventional photolithography technology, it can form high-density patterns, and can form periodic structures by phase separation of block copolymers, such as spheres, cylinders or lamellar shapes.

However, the block copolymers proposed so far have relatively low etching selectivity between the blocks to destroy the pattern, or it is difficult to reduce the line width of the pattern below a certain level, and the line edge roughness (line edge roughness, LER), line width roughness (line width roughness, LWR) and other aspects have quite a lot of defects, thereby reducing the quality of semiconductor components.

Therefore, it is currently necessary to develop a block copolymer with good etching selectivity and capable of minimizing LER and LWR to form high-quality nano patterns.

〔Related technical documents〕

[Patent Document]

Korean Patent Publication No. 10-2016-0073408 (June 24, 2016)

One embodiment of the present invention relates to a diblock copolymer with excellent etching selectivity and capable of minimizing LER and LWR to form high-quality nano-patterns.

In a general aspect, a diblock copolymer is provided, which includes a first block and a second block, the first block having a repeating unit represented by the following chemical formula 1, the second block It has a repeating unit represented by the following chemical formula 2:

[Chemical formula 2]

Wherein R ₁ to R ₄ are independently selected from the group consisting of: -H, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, a group having 2 to 10 carbon atoms Alkynyl, halo, cyano, alkoxy having 1 to 10 carbon atoms, alkylthio having 1 to 10 carbon atoms, alkylcarbonyl having 1 to 10 carbon atoms, and having 2 to 10 carbon atoms Alkenylcarbonyl of carbon atoms; R ₅ is selected from the group consisting of: -H, alkyl having 1 to 10 carbon atoms, cycloalkyl having 3 to 10 carbon atoms, having 2 to 10 carbons Atom alkenyl, cycloalkenyl having 3 to 10 carbon atoms, alkynyl having 2 to 10 carbon atoms, having 2 to 10 carbon atoms and containing any one or two or two selected from O, N and S Heterocycloalkyl groups having more heteroatoms, aryl groups having 6 to 20 carbon atoms, heteroaromatic groups having 4 to 20 carbon atoms and containing any one or two or more heteroatoms selected from O, N and S Group, halo, cyano, alkoxy having 1 to 10 carbon atoms, cycloalkoxy having 3 to 10 carbon atoms, aryloxy having 6 to 20 carbon atoms, having 1 to 10 Alkylthio groups with carbon atoms, cycloalkylthio groups with 3 to 10 carbon atoms, arylthio groups with 6 to 20 carbon atoms, alkylcarbonyl groups with 1 to 10 carbon atoms, 2 to 10 carbons -Atom alkenylcarbonyl, arylcarbonyl having 6 to 20 carbon atoms, cycloalkylcarbonyl having 3 to 10 carbon atoms, and cycloalkenylcarbonyl having 3 to 10 carbon atoms; X ₁ to X ₅ are Independently selected from the group consisting of: -H, -F, alkyl having 1 to 10 carbon atoms and substituted with at least one F, cycloalkyl having 3 to 10 carbon atoms and substituted with at least one F , The aryl groups having 6 to 20 carbon atoms and substituted by at least one F are restricted that they are not all -H.

In the diblock copolymer, when the molar fractions of repeating unit A, repeating unit B, and repeating unit C in the diblock copolymer represented by the above chemical formula 1 and chemical formula 2 are 1, n, and m, respectively When, l is 0.2 to 0.9, n is 0 to 0.6, m is 0.01 to 0.7, and l+n+m=1.

In another general aspect, a polymer film is provided that includes the diblock copolymer.

Other features and aspects will be clarified from the following embodiments, drawings, and the scope of patent application.

Figure 1 shows the etched nano patterns of Example 3 and Comparative Example 1, showing that the line width of Example 3 is narrower than that of Comparative Example 1.

Figure 2 shows the etched nano patterns of Examples 1 and 3, showing the effect of adjusting the molar% (mol%) of the repeating unit C.

Fig. 3 shows the SAXS of the block copolymers according to Example 3 and Comparative Example 1 (left) and the temperature-χ graph calculated therefrom.

The following description of the implementation aspects with reference to the accompanying drawings will clarify the advantages, features and aspects of the present invention. However, the present invention can be embodied in different forms, and should not be regarded as limited to the implementation modes set forth herein. On the contrary, these embodiments are provided so that the present invention will be thorough and complete, and will fully convey the scope of the present invention to those skilled in the art. The terminology used herein is only used for the purpose of describing specific implementation aspects, and is not intended to limit the implementation aspects. Unless the context clearly indicates otherwise, the singular forms "一 (a, an)" and "the (the)" used herein are also intended to include the plural forms. It will be further understood that when used in this specification, the term "comprises and/or comprising" designates the presence of the features, integers, steps, operations, elements and/or components, but does not exclude the presence or addition of one Or multiple other features, integers, steps, operations, elements, components, and/or groups thereof.

Hereinafter, the diblock copolymer according to the present invention will be described in detail with reference to the accompanying drawings. The drawings provided below are provided by way of examples, so that the idea of the present invention can be fully conveyed to those skilled in the present invention. Therefore, the present invention is not limited to the figures provided below, but can be modified in many different forms. In addition, the figures presented below will be enlarged to clarify the spirit and scope of the present invention. In addition, throughout the specification, the same element symbols represent the same elements.

Unless otherwise defined, the technical terms and scientific terms used herein have general meanings understood by those familiar with the present invention, and descriptions of known functions and configurations that obscure the present invention will be omitted in the following description and accompanying drawings.

基(chrysenyl)及稠四苯基等芳族基。「伸芳基(arylene group)」係為藉由移除兩個氫而衍生自芳族烴的二價有機基。「雜芳基(heteroaryl group)」係指含有選自N、O及S之任一或多個 雜原子作為芳族環骨架原子以及碳作為其餘芳族環骨架原子的單價芳基，且為5員或6員單環雜芳基或者與至少一個苯環稠合的多環雜芳基。此外，本文中之雜芳基亦包括由單鍵連接至少一個雜芳基的形式。單環雜芳基的實例，如呋喃基、噻吩基、吡咯基、吡喃基、咪唑基、吡唑基、噻唑基、噻二唑基、異噻唑基、異

唑基、

唑基、

二唑基、三嗪基、四嗪基、三唑基、四唑基、呋呫基、吡啶基、吡嗪基、嘧啶基及噠嗪基；多環雜芳基的實例，如苯並呋喃基、苯並噻吩基、異苯並呋喃基、苯並咪唑基、苯並噻唑基、苯並異噻唑基、苯並異

唑基、苯並

唑基、異吲哚基、吲哚基、吲唑基、苯並噻二唑基、喹啉基、異喹啉基、

啉基(cinnolinyl)、喹唑啉基、喹嗪基、喹

啉基、咔唑基(carbazolyl)、菲啶基及苯並二氧雜環戊烯基(benzodioxolyl)。「伸雜芳基(heteroarylene group)」為藉由移除兩個氫而衍生自雜芳族烴的二價有機基。 As used herein, "alkyl group" and "alkoxy group" refer to monovalent organic groups including both linear and branched forms. "Aryl group" refers to a monovalent organic group derived from an aromatic hydrocarbon by removal of one hydrogen, and includes a monovalent organic group containing suitably 4 to 7, preferably 5 or 6 ring atoms in each ring. A ring or fused ring system, and even a form in which a plurality of aryl groups are connected by a single bond. Specific examples of aryl groups include, for example, phenyl, naphthyl, indenyl, stilbene, phenanthryl, anthracenyl, terphenyl, pyrenyl,

Aromatic groups such as chrysenyl and fused tetraphenyl. "Arylene group" is a divalent organic group derived from aromatic hydrocarbons by removing two hydrogens. "Heteroaryl group" refers to a monovalent aryl group containing any one or more heteroatoms selected from N, O and S as the aromatic ring skeleton atoms and carbon as the remaining aromatic ring skeleton atoms, and is 5 Member or 6-membered monocyclic heteroaryl group or polycyclic heteroaryl group fused with at least one benzene ring. In addition, the heteroaryl group herein also includes a form in which at least one heteroaryl group is connected by a single bond. Examples of monocyclic heteroaryl groups, such as furyl, thienyl, pyrrolyl, pyranyl, imidazolyl, pyrazolyl, thiazolyl, thiadiazolyl, isothiazolyl, iso

Azole,

Azole,

Diazolyl, triazinyl, tetrazinyl, triazolyl, tetrazolyl, furyl, pyridyl, pyrazinyl, pyrimidinyl and pyridazinyl; examples of polycyclic heteroaryl groups, such as benzofuran Group, benzothienyl, isobenzofuranyl, benzimidazolyl, benzothiazolyl, benzisothiazolyl, benziso

Azolyl, benzo

Azolyl, isoindolyl, indolyl, indazolyl, benzothiadiazolyl, quinolinyl, isoquinolinyl,

Cinnolinyl, quinazolinyl, quinazinyl, quinoline

Linyl, carbazolyl, phenanthridinyl and benzodioxolyl. "Heteroarylene group" is a divalent organic group derived from heteroaromatic hydrocarbons by removing two hydrogens.

In the past, as a block copolymer for DSA technology, polymethyl methacrylate-b-polystyrene block copolymer (PMMA-b-PS) was often used. PMMA-b-PS has excellent pattern aspect ratio, excellent vertical alignment properties, and excellent etching selectivity in wet development.

However, when wet etching PMMA-b-PS, there is no problem in the formation of spherical or cylindrical patterns, but in the case of lamellar patterns, the PS pattern is destroyed by capillary force and the roughness is greatly increased, which makes it impossible Realize ideal pattern transfer.

Therefore, as a method of forming a sheet layer pattern, dry development using plasma or the like has been used, however, it is still difficult to reduce the line width below a certain level, and line edge roughness (LER), line width roughness (LWR) There are many defects in etc. which degrade the quality of semiconductor devices.

Therefore, the inventors have conducted long-term research to provide a block copolymer that can reduce the line width to increase the pattern density while minimizing LER and LWR to improve the quality of semiconductor devices, and in this method, they found When the block copolymer has a χ value within a specific range (middle-χ), the desired line width, LER and LWR can be achieved, and due to continuous efforts to obtain a χ value within a specific range, it is also found When the styrene group used is substituted with an appropriate amount of at least F group, a block copolymer with a value of χ within a specific range can be prepared, thereby completing the present invention.

Specifically, the block copolymer system according to the present invention may be a diblock copolymer having a first block and a second block, and the first block has a repeat represented by the following chemical formula 1. Unit, and the second block has a repeating unit represented by the following chemical formula 2:

Wherein R ₁ to R ₄ are independently selected from the group consisting of: -H, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, a group having 2 to 10 carbon atoms Alkynyl, halo, cyano, alkoxy having 1 to 10 carbon atoms, alkylthio having 1 to 10 carbon atoms, alkylcarbonyl having 1 to 10 carbon atoms, and having 2 to 10 carbon atoms Alkenylcarbonyl of carbon atoms; R ₅ is selected from the group consisting of: -H, alkyl having 1 to 10 carbon atoms, cycloalkyl having 3 to 10 carbon atoms, having 2 to 10 carbons Atom alkenyl, cycloalkenyl having 3 to 10 carbon atoms, alkynyl having 2 to 10 carbon atoms, having 2 to 10 carbon atoms and containing any one or two or two selected from O, N and S Heterocycloalkyl groups having more heteroatoms, aryl groups having 6 to 20 carbon atoms, heteroaromatic groups having 4 to 20 carbon atoms and containing any one or two or more heteroatoms selected from O, N and S Group, halo, cyano, alkoxy having 1 to 10 carbon atoms, cycloalkoxy having 3 to 10 carbon atoms, aryloxy having 6 to 20 carbon atoms, having 1 to 10 Alkylthio groups with carbon atoms, cycloalkylthio groups with 3 to 10 carbon atoms, arylthio groups with 6 to 20 carbon atoms, alkylcarbonyl groups with 1 to 10 carbon atoms, 2 to 10 carbons -Atom alkenylcarbonyl, arylcarbonyl having 6 to 20 carbon atoms, cycloalkylcarbonyl having 3 to 10 carbon atoms, and cycloalkenylcarbonyl having 3 to 10 carbon atoms; X ₁ to X ₅ are Independently selected from the group consisting of: -H, -F, alkyl having 1 to 10 carbon atoms and substituted with at least one F, cycloalkyl having 3 to 10 carbon atoms and substituted with at least one F And aryl groups having 6 to 20 carbon atoms and substituted with at least one F, with the restriction that they are not all -H.

In the diblock copolymer, when the molar fractions of repeating unit A, repeating unit B, and repeating unit C in the diblock copolymer represented by the above chemical formula 1 and chemical formula 2 are 1, n, and m, respectively When, l is 0.2 to 0.9, n is 0 to 0.6, m is 0.01 to 0.7, and l+n+m=1. Here, in Chemical Formula 2, -co- means a copolymer.

More specifically, the second block having the repeating unit represented by Chemical Formula 2 may be a random copolymer in which the repeating units represented by B and C are randomly distributed, or in which the repeating units are bonded in an alternating manner An alternating copolymer, and preferably it may be a random copolymer.

In this way, the diblock copolymer including the first block satisfying chemical formula 1 and the second block satisfying chemical formula 2 can have very good vertical orientation properties, thereby forming a vertical through the self-assembly process in a very short time. Oriented sheet-layer patterns, and almost perfectly aligned nano-patterns are formed even on large-area substrates. In addition, the etching selectivity between the two blocks is excellent, which reduces LER and LWR during development. Here, the self-assembly process is not particularly limited, as long as it is commonly used in the field for spontaneous self-assembly block copolymers, and as a specific example, thermal annealing, solvent annealing or a combination thereof can be used.

More preferably, in the diblock copolymer according to the exemplary embodiment of the present invention, R ₁ to R ₄ may be independently selected from the group consisting of: -H, an alkyl group having 1 to 10 carbon atoms , Alkenyl groups with 2 to 10 carbon atoms and alkynyl groups with 2 to 10 carbon atoms.

In the diblock polymer according to an exemplary embodiment of the present invention, R ₅ is selected from the group consisting of: -H, an alkyl group having 1 to 10 carbon atoms, a ring having 3 to 10 carbon atoms Alkyl, alkenyl having 2 to 10 carbon atoms, cycloalkenyl having 3 to 10 carbon atoms, alkynyl having 2 to 10 carbon atoms, having 2 to 10 carbon atoms and containing selected from O, Any one of N and S or a heterocycloalkyl group of two or more heteroatoms, an aryl group having 6 to 20 carbon atoms, having 4 to 20 carbon atoms and containing any one selected from O, N and S or Heteroaryl groups with two or more heteroatoms, halo groups, cyano groups, alkoxy groups with 1 to 10 carbon atoms, cycloalkoxy groups with 3 to 10 carbon atoms, and those with 6 to 20 carbon atoms Aryloxy, alkylthio having 1 to 10 carbon atoms, cycloalkylthio having 3 to 10 carbon atoms, arylthio having 6 to 20 carbon atoms, alkane having 1 to 10 carbon atoms Carbonyl, alkenylcarbonyl having 2 to 10 carbon atoms, arylcarbonyl having 6 to 20 carbon atoms, cycloalkylcarbonyl having 3 to 10 carbon atoms, and cycloalkenes having 3 to 10 carbon atoms基carbonyl.

In the diblock polymer according to an exemplary embodiment of the present invention, X ₁ to X ₅ are independently selected from the group consisting of: -H, -F, having 1 to 10 carbon atoms and having at least one F Substituted alkyl groups, cycloalkyl groups having 3 to 10 carbon atoms and substituted with at least one F, and aryl groups having 6 to 20 carbon atoms and substituted with at least one F, with the restriction that none of them are -H .

In addition, in the diblock polymer according to the exemplary embodiment of the present invention, the molar ratio of the repeating unit A, the repeating unit B, and the repeating unit C in the diblock copolymer represented by the above Chemical Formula 1 and Chemical Formula 2 When the fractions are l, n, and m, l is 0.35 to 0.8, n is 0.1 to 0.5, m is 0.1 to 0.5, and l+n+m=1.

By including the first block and the second block satisfying the foregoing, the diblock copolymer according to the exemplary embodiment of the present invention can ensure a sheet layer pattern having excellent quality. However, in order to effectively form a layer pattern and ensure a high-quality pattern, as described below, it is preferable to adjust the molar fraction of each repeating unit differently according to the number of introduced fluorine groups.

Preferably, in the diblock copolymer according to an exemplary embodiment of the present invention, the second block may satisfy the following chemical formula 3:

Wherein, R ₃ to R ₅ , n and m are defined as in Chemical Formula 2.

More preferably, in Chemical Formula 3, R ₃ and R ₄ can be independently selected from the group consisting of -H and an alkyl group having 1 to 10 carbon atoms; R _{5 can be} selected from -H, having 1 to 10 The group consisting of an alkyl group having carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, and an aryloxy group having 6 to 20 carbon atoms; and n may be 0.1 to 0.5, m can be 0.1 to 0.5, and l+n+m can be 1. Here, l may be as defined in Chemical Formula 1, more preferably 0.35 to 0.8.

Therefore, by introducing the repeating unit C having a pentafluorostyrene group into the second block, the etching rate can be significantly reduced compared with the first block, so the LER and LWR of these patterns can be greatly reduced.

In addition, in the exemplary embodiment of the present invention, the molar fraction of each unit block, particularly the molar fraction of the repeating unit B may be based on the number of fluorine-containing substituents substituted in the repeating unit C And adjust differently.

Specifically, when X ₁ to X ₅ may all be substituted with fluorine-containing substituents, n may be 0.01 to 0.6, and when X ₁ to X ₅ have at least one -H, n may be 0 to 0.6.

That is, according to the diblock polymer of the exemplary embodiment of the present invention, X ₁ to X ₅ can be independently selected from the group consisting of: -H, -F, having 1 to 10 carbon atoms and having at least An F-substituted alkyl group, a cycloalkyl group with 3 to 10 carbon atoms and at least one F-substituted, and an aryl group with 6 to 20 carbon atoms and at least one F-substituted, with the restriction that none of them are -H; and when the molar fractions of repeating unit A, repeating unit B, and repeating unit C in the diblock copolymer are l, n, and m, respectively, l is 0.2 to 0.9, and n is 0.01 to 0.6, m is 0.01 to 0.7, and l+n+m=1.

Specifically, when a pentafluorostyrene group is included as the repeating unit C, the lamellar pattern can be formed more efficiently and stably by satisfying that l is 0.4 to 0.6, n is 0.2 to 0.4, and m is 0.1 to 0.3.

In addition, according to the diblock polymer of another exemplary embodiment of the present invention, X ₁ to X ₅ can be independently selected from the group consisting of: -H, -F, having 1 to 10 carbon atoms and having At least one F-substituted alkyl group, a cycloalkyl group having 3 to 10 carbon atoms and at least one F-substituted, and an aryl group having 6 to 20 carbon atoms and at least one F-substituted, the restriction conditions are X ₁ to At least one but not more than four of X ₅ must have a -H group; and when l, n and m are the molar fractions of repeating unit A, repeating unit B and repeating unit C in the diblock copolymer, respectively , L can be 0.2 to 0.9, n can be 0 to 0.6, m can be 0.01 to 0.7, and l+n+m can be 1.

Specifically, when a fluorostyrene group containing one fluorine group is included as the repeating unit C, the sheet can be formed more efficiently and stably by satisfying that l is 0.4 to 0.6, n is 0 to 0.1, and m is 0.4 to 0.6. Layer pattern.

At the same time, it is also preferable to select the type of the first block as the first block, and specifically, it is preferable to use the first block formed from an alkyl methacrylate compound as the first block to improve the relative For the etch selectivity of the second block. More specifically, for example, the first block may be polymethyl methacrylate (PMMA), polyethyl methacrylate (PEMA), polypropyl methacrylate (PPMA), and poly(3-butyl methacrylate). Esters (PMBA) and so on. Particularly preferably, by using PMMA as the first block, the etching selectivity relative to the second block can be significantly improved. However, it is not good that the first block contains a ring structure such as an aromatic group or an alicyclic group, because the etching properties may be deteriorated by the ring structure to reduce the etching selectivity relative to the second block, and it is difficult to change the χ value. Adjusting to an appropriate range makes it difficult to form a lamellar pattern.

Particularly preferably, PMMA is used as the first block, and a compound having a repeating unit satisfying Chemical Formula 3 may be used as the second block. Therefore, it is possible to provide a diblock copolymer with maximized etching properties, which greatly reduces the line width, thereby significantly improving the pattern density and ensuring high-quality patterns. Specifically, the diblock copolymer according to the exemplary embodiment of the present invention may form a pattern with an LER of 3.3 nanometers or less and an LWR of 4.5 nanometers or less. Here, the lower limit of LER and LWR may be the lowest possible value, and specifically, for example, 0.1 nm or more.

As mentioned above, the diblock copolymer containing the first block and the second block can be used to form a periodic and vertically aligned sheet layer pattern, and in order to improve efficiency, it is preferable to change the χ(chi) of the diblock copolymer The value is adjusted to an appropriate range, where χ is the Flory-Huggins interaction parameter, which is the digitized value of the interaction between the first block and the second block, and is based on the Lay-Huggins interaction parameter. Leibler's mean field theory is calculated based on the measurement of small-angle X-ray scattering (SAXS).

Specifically, together with the results obtained from the SAXS measurement, the χ value of the block copolymer can be obtained according to the theoretical formula of Leibler's mean field theory, and the derivation process is as follows: I(q)=K[S(q )/W(q)-2χ] ^-1

S(q)=<S _x,x (q)> _v +2<S _x,y (q)> _v +<S _y,y (q)> _v

W(q)=<S _x,x (q)> _v *<S _y,y (q)> _v -<Sy,y(q)> _v ²

<S _x,x (q)> _v = r _c,n f _x ² _,n g _x ⁽²⁾ _,n (q)

<S _x,y (q)> _v = r _c,n f _x f _y g _x ⁽¹⁾ _,n (q)g _y ⁽¹⁾ _,n (q)

r _c,n = (v _x N _x,n +v _y N _y,n )/(v _x * v _y ) ^1/2

g _x ⁽¹⁾ _,n (q)=1/x _x,n {1-[x _x,n (λ _x -1)+1] ^-(λx-1)-1 }

g _x ⁽²⁾ _,n (q)=1/x _x,n ² {-1+[x _x,n (λ _x -1)+1] ^-(λx-1)-1 }

x _x,n = (N _x,n b _x ² /6)q ²

λ _x,n =N _x,w /N _x,n

Where v _x is the molar volume of X (cubic centimeters/mole (cm ³ /mol)), and f _X is the volume ratio of X. N _x,n and N _x,w are the number average degree of polymerization and weight average degree of polymerization of the X block; and b _x is the fragment length of X. Unless otherwise specified, the χ value of the block copolymer obtained from the SAXS measurement results and the above calculation formula refers to the χ value at 25°C.

For a more detailed calculation method, you can refer to Leibler, L., "The Theory of Microphase Separation in Block Copolymers", Macromolecules 1980, 13, 1602-1617 (Leibler, L., "Theory of Microphase Separation in Block Copolymers", Macromolecules 1980, 13, pp. 1602-1617) and Hashimoto, T et al., "Ordered and disordered transformation of low molecular weight polystyrene-block-polyisoprene" 1. SAXS at two characteristic temperatures Analysis, Macromolecules 1995, 28, 6825-6834 pages (Hashimoto, T., et al., "Order-Disorder Transition of Low Molecular Weight Polystyrene-block-Polyisoprene. 1. SAXS Analysis of Two Characteristic Temperatures", Macromolecules 1995, 28, pp. 6825-6834). For example, for the calculation method of PMMA-b-PS diblock copolymer, see Zhao, Y. et al., "The Order and Disorder Transformation of Polystyrene-Block-Poly(methyl methacrylate) and SAXS Analysis of Interaction Parameters", Macromolecule 2008, 41, 9948-9951 pages (Zhao, Y., et al., "SAXS Analysis of the Order-Disorder Transition and the Interaction Parameter of Polystyrene-block-poly(methyl methacrylate) )", Macromolecules 2008, 41, pp. 9948-9951). The matters described in the above three papers are considered to be the same as described in this article.

Specifically, the diblock copolymer according to an exemplary embodiment of the present invention may have a χ value of 0.01 to 0.26 at 25°C, and more preferably may have a χ value of 0.035 to 0.10 at 25°C. Within this range, the diblock copolymer can effectively form a pattern with a lamellar structure through a self-assembly process, and reduce LER and LWR.

Therefore, the χ value can be adjusted according to the molecular weight of the diblock copolymer and the molar fraction of the repeating unit C introduced into the second block.

Specifically, the diblock copolymer according to an exemplary embodiment of the present invention may satisfy the following equation 1:

Wherein M _{n is} the number average molecular weight of the diblock copolymer; m is the molar fraction of the repeating unit C; and a is the number of F introduced into the repeating unit C.

Therefore, equation 1 can be satisfied by adjusting the number average molecular weight of the diblock copolymer, the molar fraction of the repeating unit C introduced into the second block, and the number of F introduced into the repeating unit C, so that The χ value is in the range of 0.035 to 0.10. Here, the number of F introduced into the repeating unit C does not refer to the number of F introduced into the entire diblock copolymer, but the number of F in the chemical formula of one repeating unit C. For example, when the diblock copolymer satisfies the chemical formula 3, a is 5, when only _{any one of X 1} to X ₅ is substituted by F, a is 1, and when X ₁ to X _{5 are} all substituted by CF ₃ When, a is 15.

As a non-limiting example, the number average molecular weight of the diblock copolymer according to an exemplary embodiment of the present invention may be 5,000 grams/mole (g/mol) to 500,000 grams/mole, preferably 10,000 grams/mole To 300,000 grams/mole. As a non-limiting example, the polydispersity index (PDI; molecular weight distribution; Mw/Mn) of the diblock copolymer can be 1.5 or less, preferably 1.0 to 1.2. The polydispersity index refers to the value obtained by dividing the weight average molecular weight by the number average molecular weight, and it can usually be measured by size exclusion chromatography (SEC or GPC) under the measurement conditions known in the art Calculation.

It is preferable to satisfy the number average molecular weight and the polydispersity index, because a vertically-oriented sheet pattern can be obtained even on a large-area substrate without defects, but the present invention is not limited to the above numerical range.

Specifically, according to the diblock copolymer of the present invention, the weight ratio of the first block having the repeating unit represented by the following chemical formula 1 to the second block having the repeating unit represented by the following chemical formula 2 can be 1 : 0.3 to 0.7, preferably 1: 0.4 to 0.6.

As described above, the diblock copolymer according to the present invention can be excellent by including a first block having a repeating unit represented by the following Chemical Formula 1 and a second block having a repeating unit represented by the following Chemical Formula 2 Etching selectivity.

Specifically, the diblock copolymer according to the exemplary embodiment of the present invention may have an etching selectivity that satisfies the following equation 2:

Where ER _{1 is} the etching rate of the first block (nm/sec (nm/sec)); ER _{2 is} the etching rate of the second block (nm/sec); and the etching rates (nanometres) /Sec) Each of them is calculated from the following calculation formula 1: [Calculation formula 1] Etching rate = (T ₀ -T ₁ )/S

Where T ₀ is the initial thickness (in nanometers (nm)) of the first block or the second block before etching _{; T 1 is the final thickness of the first block or the second block after etching} Thickness (nm); and S is the etching time (seconds (sec)).

That is, when etching at the same time, the first block can be etched four or more times faster than the second block. Therefore, the first block can be etched clearly while minimizing damage to the second block.

Therefore, by using a block copolymer including a first block having a repeating unit represented by Chemical Formula 1 and a second block having a repeating unit represented by Chemical Formula 2, the etching selectivity can be maximized, and therefore, it can be formed with Reduced line width, high-quality fine patterns of LER and LWR.

Hereinafter, the diblock copolymer of the present invention will be described in more detail with the following examples. However, the following examples are only reference for describing the present invention in detail, and the present invention is not limited thereto and can be implemented in various forms.

In addition, unless otherwise defined, all technical terms and scientific terms have the same meanings as commonly understood by those familiar with the present invention. The terminology used herein is only used to effectively describe a certain exemplary embodiment, and is not intended to limit the present invention. In addition, unless otherwise specified, the unit of the materials added herein may be weight% (wt%).

[Example 1]

烷中(總濃度：60重量%)，並在氮氣氛下在70℃下反應24小時，以合成由包含聚甲基丙烯酸甲酯(PMMA)的第一嵌段以及包含苯乙烯及五氟苯乙烯無規共聚物的第二嵌段組成的二嵌段共聚物(數量平均分子量：95,200，分子量分佈：1.2)。使用NMR分析由此製得的二嵌段共聚物，以確認每一重複單元之莫耳分率。 AIBN (azobisisobutyronitrile), RAFT reagent (cyanoisopropyl dithiobenzoate) and methyl methacrylate were dissolved in benzene at a molar ratio of 1:5:2800 (total concentration: 50 Weight%) and reacted at 80°C for 6 hours under a nitrogen atmosphere to synthesize a macroinitiator (number average molecular weight: 45,400, molecular weight distribution: 1.2). Then, the macroinitiator, AIBN, styrene (ST) and pentafluorostyrene (PFS) were dissolved in a molar ratio of 1:0.2:900:100.

In alkane (total concentration: 60% by weight), and reacted at 70°C for 24 hours under a nitrogen atmosphere to synthesize the first block containing polymethylmethacrylate (PMMA) and containing styrene and pentafluorobenzene A diblock copolymer composed of the second block of an ethylene random copolymer (number average molecular weight: 95,200, molecular weight distribution: 1.2). The diblock copolymer thus prepared was analyzed using NMR to confirm the molar fraction of each repeating unit.

[Examples 2 to 4]

Using the macroinitiator of Example 1, relative to the macroinitiator, AIBN is 20 mol%, and the number of mols of styrene (ST) and pentafluorostyrene (PFS) is changed as described in Table 1 below, Thus, a diblock copolymer was synthesized.

[Example 5]

烷中(總濃度：60重量%)，並在氮氣氛下在70℃下反應24小時，以合成二嵌段共聚物(數量平均分子量：42,200，分子量分佈：1.21)。使用NMR分析由此製得的二嵌段共聚物，以確認每一重複單元之莫耳分率。 Dissolve AIBN (azobisisobutyronitrile), RAFT reagent (cyanoisopropyl dithiobenzoate) and methyl methacrylate (MMA) in a molar ratio of 1:5:1500 in benzene (total Concentration: 50% by weight), and reacted at 80°C for 6 hours in a nitrogen atmosphere to synthesize a macroinitiator (number average molecular weight: 21,500, molecular weight distribution: 1.2). Then, the macroinitiator, AIBN, styrene (ST) and pentafluorostyrene (PFS) were dissolved in a molar ratio of 1:0.2:450:50.

In alkane (total concentration: 60% by weight), and reacted at 70°C for 24 hours in a nitrogen atmosphere to synthesize a diblock copolymer (number average molecular weight: 42,200, molecular weight distribution: 1.21). The diblock copolymer thus prepared was analyzed using NMR to confirm the molar fraction of each repeating unit.

[Examples 6 to 8]

The macroinitiator of Example 2 was used, and the molar numbers of styrene (ST) and pentafluorostyrene (PFS) were changed as described in Table 1 below to synthesize a diblock copolymer.

[Example 9]

Except for using tert-butyl acrylate instead of methyl methacrylate, all processes were performed in the same manner as in Example 6.

[Example 10]

Except that the number of moles of each monomer was changed as described in Table 1 below, the process was performed in the same manner as in Example 1, thereby synthesizing a diblock copolymer.

[Example 11]

Except that the number of moles of each monomer was changed as described in Table 1 below, the process was performed in the same manner as in Example 5 to synthesize a diblock copolymer.

[Example 12]

烷中(總濃度：60重量%)，並在氮氣氛下在70℃下反應24小時，以合成二嵌段共聚物(數量 平均分子量：42,100，分子量分佈：1.19)。使用NMR分析由此製得的二嵌段共聚物，以確認每一重複單元之莫耳分率。 Dissolve AIBN (azobisisobutyronitrile), RAFT reagent (cyanoisopropyl dithiobenzoate) and methyl methacrylate (MMA) in a molar ratio of 1:5:1500 in benzene (total Concentration: 50% by weight), and reacted at 80°C for 6 hours in a nitrogen atmosphere to synthesize a macroinitiator (number average molecular weight: 20,900, molecular weight distribution: 1.11). Then, the macroinitiator, AIBN and 4-fluorostyrene were dissolved in a molar ratio of 1:0.2:700.

In an alkane (total concentration: 60% by weight), and reacted at 70°C for 24 hours in a nitrogen atmosphere to synthesize a diblock copolymer (number average molecular weight: 42,100, molecular weight distribution: 1.19). The diblock copolymer thus prepared was analyzed using NMR to confirm the molar fraction of each repeating unit.

[Comparative Example 1]

Except that the number of moles of each monomer was changed as described in Table 1 below, the process was performed in the same manner as in Example 1, thereby synthesizing a diblock copolymer.

[Comparative Example 2]

Except that the number of moles of each monomer was changed as described in Table 1 below, the process was performed in the same manner as in Example 5 to synthesize a diblock copolymer.

[Comparative Example 3]

Except for using phenyl methacrylate instead of methyl methacrylate, all procedures were performed in the same manner as in Example 1.

[Comparative Example 4]

Except for using phenyl methacrylate instead of methyl methacrylate, all procedures were performed in the same manner as in Example 5.

〔Experimental example 1〕

The diblock copolymer synthesized in Example 1 to Example 12 and Comparative Example 1 to Comparative Example 4 was dissolved in a solvent at a concentration of about 1.0% by weight, and then spin-coated on the silicon crystal at a speed of 4000 revolutions per minute (rpm) 30 seconds on the circle.

Thereafter, thermal annealing was performed at 225°C for 12 hours to perform self-assembly.

Then, in order to remove the PMMA block in the block copolymer film, reactive ion etching (RIE) is performed. Here, the reactive plasma (RF) power is 60 watts (W), the reactive plasma injection rate is 45 standard cubic centimeters per minute (sccm), the pressure is 30 millitorr (mTorr), and the Etching was performed under the voltage of 170 volts (V) to remove the first block. The micrograph of the polymer film was taken by scanning electron microscope (SEM) or atomic force microscope (AFM) and measured with SuMMIT software CD, LER and LWR of self-assembled patterns. In addition, the etching selectivity was calculated according to Equation 2 below, and is shown in Table 3.

[Equation 2] ER ₁ /ER ₂

Where ER ₁ is the etch rate of the first block (nanometers/sec); and ER ₂ is the etch rate of the second block (nanometres/sec).

[Calculation formula 1] Etching rate = (T ₀ -T ₁ )/S

Wherein T ₀ is the initial thickness (nm) _{of the first block or the second block before etching; T 1} is the final thickness (nm) of the first block or the second block after etching; and S is the etching time (seconds).

In Table 2 above, F _PFS refers to the mole fraction of the pentafluorostyryl (PFS) repeating unit contained in the above chemical formula 2, specifically PFS mole number/(ST mole number + PFS mole number ).

As shown in Table 1, the repeating unit C into which the F group was introduced according to the present invention was introduced, and the molar fraction of each repeating unit was adjusted to prepare a diblock copolymer.

As a result, in Examples 1 to 12, it was confirmed that a pattern having a lamellar structure was formed.

Among them, as shown in Fig. 2, it is confirmed that the pentafluorostyryl group is contained as the repeating unit C and that the molar fraction of the repeating unit C is 0.1 to 0.3 is satisfied in Example 2, Example 3, Example 6, Example 7, and Example 9 The χ value ranges from 0.035 to 1, so that lamellar patterns are formed very efficiently, and when fine patterns are formed by etching these, as shown in Table 3 below, it is confirmed that extremely high-quality fine patterns are formed.

At the same time, Example 1, Example 4, Example 5, and Example 8 contained pentafluorostyryl as the repeating unit C, but the molar fraction of the repeating unit C far exceeded the range of 0.1 to 0.3, so it was confirmed that the lamellae were effectively formed The structure pattern, however, as shown in Table 3 below, the quality of the fine pattern after etching is greatly deteriorated.

In addition, the molar fraction of the repeating unit C of Example 10 and Example 11 significantly exceeded the range of 0.1 to 0.3, and therefore, the formed lamellar structure pattern was quite unstable.

Although the molar fraction of the repeating unit C of Example 12 significantly exceeded 0.3, the number of F introduced into the styrene group was 1. Therefore, it was confirmed that the number of F contained in the entire diblock copolymer was appropriately adjusted to Form a layer structure pattern.

However, in Comparative Example 1, a lamellar structure pattern was formed, and as described in the evaluation of etching properties and Table 3 below, it was confirmed that the etching selectivity was lowered compared with each example, thereby deteriorating the pitch, CD, LWR And the nature of LER.

In Comparative Example 3, the formed sheet layer pattern was quite unstable, and as described in the evaluation of etching properties and Table 3 below, it was confirmed that the etching selectivity was lowered compared with each example, thereby deteriorating the pitch, CD, and LWR. And the nature of LER.

It can be seen from Table 3 that the etch resistance of the fluorine-introduced unit block C is increased, thereby significantly improving the etching selectivity, so that high-quality fine patterns can be prepared after etching.

In particular, in Example 3, Example 7, and Example 12, it has been confirmed that the etching selectivity between the blocks is 5 or more, which is much better than that of Comparative Example 1. Especially in Example 7, the line width, LWR and LER are higher. Small, that is, they are about 75%, about 68%, and about 81%, respectively, compared to those of Comparative Example 1, so it is confirmed that high-quality patterns are formed.

According to the present invention, the diblock copolymer containing the first block and the second block can have excellent vertical orientation properties, thereby forming a vertically-oriented sheet pattern through a self-assembly process in a very short time, and A nano pattern with almost perfect alignment is formed even on a large-area substrate. In addition, the etching selectivity between the two blocks is excellent, which greatly reduces LER and LWR during development.

In the above, although the present invention has been described through specific matters and limited examples, they are only provided to help a complete understanding of the present invention. Therefore, the present invention is not limited to the above examples. Those who are familiar with the technology of the present invention can make various modifications and changes from this specification.

Therefore, the spirit of the present invention should not be limited to the above exemplary embodiments, and the scope of the attached patent application and all modifications that are the same or equivalent to the scope of the patent application fall within the scope and spirit of the present invention.

Claims (12)

A diblock copolymer comprising a first block and a second block, the first block having a repeating unit represented by the following chemical formula 1, and the second block having a repeating represented by the following chemical formula 3 unit:

Wherein R ₁ to R ₄ are independently selected from the group consisting of: -H, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, a group having 2 to 10 carbon atoms Alkynyl, halo, cyano, alkoxy having 1 to 10 carbon atoms, alkylthio having 1 to 10 carbon atoms, alkylcarbonyl having 1 to 10 carbon atoms, and having 2 to 10 carbon atoms Alkenylcarbonyl of carbon atoms; R ₅ is selected from the group consisting of: -H, alkyl having 1 to 10 carbon atoms, cycloalkyl having 3 to 10 carbon atoms, having 2 to 10 carbons Atom alkenyl, cycloalkenyl having 3 to 10 carbon atoms, alkynyl having 2 to 10 carbon atoms, having 2 to 10 carbon atoms and containing any one or two or two selected from O, N and S Heterocycloalkyl groups having more heteroatoms, aryl groups having 6 to 20 carbon atoms, heteroaromatic groups having 4 to 20 carbon atoms and containing any one or two or more heteroatoms selected from O, N and S Group, halo, cyano, alkoxy having 1 to 10 carbon atoms, cycloalkoxy having 3 to 10 carbon atoms, aryloxy having 6 to 20 carbon atoms, having 1 to 10 Alkylthio groups with carbon atoms, cycloalkylthio groups with 3 to 10 carbon atoms, arylthio groups with 6 to 20 carbon atoms, alkylcarbonyl groups with 1 to 10 carbon atoms, 2 to 10 carbons Atoms of alkenylcarbonyl, arylcarbonyl having 6 to 20 carbon atoms, cycloalkylcarbonyl having 3 to 10 carbon atoms, and cycloalkenylcarbonyl having 3 to 10 carbon atoms; and in the diblock In the copolymer, when the molar fractions of repeating unit A, repeating unit B, and repeating unit C in the diblock copolymer represented by the above chemical formula 1 and chemical formula 3 are 1, n, and m, respectively, l is 0.4 To 0.6, n is 0.2 to 0.4, m is 0.1 to 0.3, and l+n+m=1, and the diblock copolymer has an χ value of 0.035 to 0.10 at 25°C. The diblock copolymer according to claim 1, wherein the first block is formed from an alkyl methacrylate compound. The diblock copolymer according to claim 1, wherein the block copolymer satisfies the following equation 1:

Wherein M _{n is} the number average molecular weight of the diblock copolymer; m is the molar fraction of the repeating unit C; and a is the number of F introduced into the repeating unit C. The diblock copolymer according to claim 1, wherein the block copolymer has an etching selectivity that satisfies the following equation 2: [Equation 2]

Where ER _{1 is} the etching rate of the first block (nm/see); ER _{2 is} the etching rate of the second block (nm/sec); and each of the etching rates One is calculated from the following calculation formula 1: [Calculation formula 1] etching rate=(T ₀ -T ₁ )/S where T ₀ is the initial thickness of the first block or the second block before etching ( Nano); T ₁ is the final thickness of the first block or the second block after etching (in nanometers); and S is the etching time (seconds). The diblock copolymer according to claim 1, wherein the diblock copolymer forms a vertically oriented sheet pattern. The diblock copolymer according to claim 1, wherein the diblock copolymer forms a pattern having an LER of 3.3 nanometers or less and an LWR of 4.5 nanometers or less. A diblock copolymer comprising a first block and a second block, the first block having a repeating unit represented by the following chemical formula 1, and the second block having a repeating represented by the following chemical formula 4 unit:

[Chemical formula 4]

Wherein, R ₁ to R ₄ are independently selected from the group consisting of: -H, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, and an alkenyl group having 2 to 10 carbon atoms Alkyl, halo, cyano, alkoxy having 1 to 10 carbon atoms, alkylthio having 1 to 10 carbon atoms, alkylcarbonyl having 1 to 10 carbon atoms and having 2 to 10 Alkenyl carbonyl group with three carbon atoms; R ₅ is selected from the group consisting of: -H, an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, having 2 to 10 carbon atoms Alkenyl of carbon atoms, cycloalkenyl of 3 to 10 carbon atoms, alkynyl of 2 to 10 carbon atoms, 2 to 10 carbon atoms and containing any one or two selected from O, N and S Heterocycloalkyl groups with or more heteroatoms, aryl groups with 6 to 20 carbon atoms, heterocycles with 4 to 20 carbon atoms and containing any one or two or more heteroatoms selected from O, N and S Aryl, halo, cyano, alkoxy having 1 to 10 carbon atoms, cycloalkoxy having 3 to 10 carbon atoms, aryloxy having 6 to 20 carbon atoms, having 1 to 10 Alkylthio groups with 3 to 10 carbon atoms, cycloalkylthio groups with 3 to 10 carbon atoms, arylthio groups with 6 to 20 carbon atoms, alkylcarbonyl groups with 1 to 10 carbon atoms, 2 to 10 carbon atoms Alkenyl carbonyl groups having carbon atoms, aryl carbonyl groups having 6 to 20 carbon atoms, cycloalkyl carbonyl groups having 3 to 10 carbon atoms, and cycloalkenyl carbonyl groups having 3 to 10 carbon atoms; In the segment copolymer, when the molar fractions of repeating unit A, repeating unit B, and repeating unit C in the diblock copolymer represented by the above chemical formula 1 and chemical formula 4 are 1, n, and m, respectively, l is 0.4 to 0.6, n is 0 to 0.1, m is 0.4 to 0.6, and l+n+m=1, and the diblock copolymer has a χ value of 0.035 to 0.10 at 25°C. The diblock copolymer according to claim 7, wherein the first block is formed from an alkyl methacrylate compound. The diblock copolymer according to claim 7, wherein the block copolymer satisfies the following equation 1:

Wherein M _{n is} the number average molecular weight of the diblock copolymer; m is the molar fraction of the repeating unit C; and a is the number of F introduced into the repeating unit C. The diblock copolymer according to claim 7, wherein the block copolymer has an etching selectivity that satisfies the following equation 2:

Where ER _{1 is} the etching rate of the first block (nm/sec); ER _{2 is} the etching rate of the second block (nm/sec); and each of the etching rates One is calculated from the following calculation formula 1: [Calculation formula 1] etching rate=(T ₀ -T ₁ )/S where T ₀ is the initial thickness of the first block or the second block before etching ( Nano); T ₁ is the final thickness of the first block or the second block after etching (in nanometers); and S is the etching time (seconds). The diblock copolymer according to claim 7, wherein the diblock copolymer forms a vertically oriented sheet pattern. The diblock copolymer according to claim 7, wherein the diblock copolymer forms a pattern having an LER of 3.3 nanometers or less and an LWR of 4.5 nanometers or less.

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